Added 2 new blocks + other little improvements.

* Added new block: invincible barrier.
* Added new block: semi-super barrier.
* Added grid for helping players learn on arena. (show with ctrl shift G)
* Made it so similar colors are treated as identical.
* When picking character color right click goes back.
* In map editor lazers can be set to be silent. In which case they wont make any SFX
* Menu option in options that opens maps folder.
* Also changed how replay folder is opened, to maybe fix an issue with that.
* Replays are named yyyy-MM-dd_HH-mm-ss now.